Position sensitive liquid conductor switch



April 17, 1962 .1. l. HENSLEY POSITION SENSITIVE LIQUID CONDUCTOR SWITCH 2 Sheets-Sheet 1 Filed NOV. 4, 1960 INVENTOR.

Jack I. Hensley ATTORNEY April 17, 1962 J. HENSLEY POSITION SENSITIVE LIQUID CONDUCTOR SWITCH Filed Nov. 4, 1960 2 Sheets-Sheet 2 INVENTOR. Jack I. Hens/e y ATTORNEY United States Patent 3,030,477 POSITION SENSITIVE LIQUID CONDUCTOR SWITCH Jack Isaac Hensley, 755 Percy St., Greensboro, N.C. Filed Nov. 4, 1960, Ser. No. 67,194

25 Claims. (Cl. 200--152) i This invention relates to a gravity operated position sensitive switch utilizing a liquid conductor and WhlCh may be adapted to close and open circuits upon being tilted from one position to another.

An object of my invention is to provide a gravity operated liquid conductor switch utilizing a liquid conductor pool that can flow to any of several electrodes depending on the direction of tilt and in which each electrode position is adjustable with respect to the pool such that the angle at which the switch operates in a given tilt directio can be adjusted.

Another object of my invention is to provide a gravity operated liquid conductor switch utilizing a liquid conductor pool that can flow to any of several electrodes de-' pending on the direction of tilt and in which the rate of flow to the electrodes can be adjusted for fast and slow switch action. I

A further object of my invention is to provide a gravlty operated liquid conductor switch utilizing a liquid controdes in any of several directions and at anyof a wide range of tilt angles between zero and substantially ninety degrees. x

Another object is to provide a gravity operated liquid conductor switch having the aforesaid features and characteristics and which is particularly adaptable to being made in compact form.

- The above and other objects will become apparent .as the description proceeds. I

1 Briefly, the switch of my invention in the embodiment described utilizes transparent, non-conductive material and includes as its base a circular block of such material;

which normally rests on its bottom surface. A chamber for holding a pool of liquid conductor; is formed in the, center and-between the top and bottom surfaces of the block.. Leading horizontally and radiallyfrom the chanther and; passing throughthe side of the block are a num-t ber of channels such that the liquidconductor may reside in both the chamber and the channels. A hollow tube of the same type material is connected to each of; the

radial channels and each tube extends above the base.- When theswitch is tilted, the liquid conductor flowsinthe-direction of. tilt through those channels and tubes located in the same direction. Compactness in the overall switch and adaptability to a high degree of. tilt,-i t the orderof'ninety degrees in all directions, are achieved by fixing each tube so as to reside above and at an acute vertical. angle with respect to the normal-plane of the switch and .at an acute projected horizontal angle with. respect to the axis of' the radial channel to which the tubeis connected. The tubes thusfall into a sort of converging and overlapping arrangement above the base.

.1 Leading into the chamber referred to abo-ve is acornmon electrode which is always in electrical contactjwith any' liquid conductorin the chamber andwithineachtube there is anelectrde which may be fixed but which preferably is adjustable as to position such that a conducting path'can be completed between the common electrode and any tube electrode by tilting the switch in the direc tion in which the electrode is located with respect to the common electrode and at a sufficient angle of tilt correportion of the switch being broken away to sponding to the particular position of the electrode. The rate at which the conducting path is established is controlled by providing adjustable means for outside air to enter and leave the normally closed end of the tube makes and breaks contact with the electrode is thus regulated. The invention further contemplates the alternative useof double electrodes in each tube and other modifications which will become apparent as the description proceeds :and in the drawings, in which:

FIGURE 1 is an elevation view of the switch. FIGURE 2 is a bottom plan view of the switch. FIGURE 3 is a top plan view of the switch, theupper illustrate location of the base electrode.

, FIGURE 4 is a sectional view taken along line 44 of FIGURE 3. e

FIGURE 5 is a partial sectional view to show the electrode mounting and air control arrangement.

FIGURE 6 shows the switch of FIGURE '1 in a tilted and partly cut away view and with a circuit to illustrate the electrode action.

FIGURE 7 schematically illustrates an alternative type circuit for the electrodes.

FIGURE 8 is a view showing a pair of adjustable elec trodes mounted in the end of one of the switch tubes and,

including a representative circuit.

. FIGURE 9 is similar to FIGURE 8 and shows how the members of the electrode pair may be placed in different positions so as to function at different angles of tilt.

FIGURE 10 shows a circuit arrangement for using an electrically conductinghousing for the liquid conductor.

-Referring particularly to FIGURES 1 through 5, the

switch includes a cylindrical block 15 of transparent, nonconductive material, having a top face 16, a bottom face 17 and a sidepface 18. A series of holes 19 are drilled radially through side face 18 to the center of block 15- so as to form an internal cylindrical shaped chamber 20.-

Holes 19 thus form the chamber 20as well as horizontal channels leading radially outward between top and bottom faces-16, 17 and from chamber 20 in which a pool ofv liquid conductor 21, such as mercury, may be confined. Whilerthe number of radialholes 19 may vary, I havefound that eight such holes as illustrated in the drawings are sufiicient for a wide variety of applications of the 22 by. reason of these tubes being mounted in the radial channels formed by holes 19. A suitable cement is used to prevent leakage between tubes '22 and holes 19. Cementedto tubes 22 are additional hollow tubes 23 which are fixed in a position that places the axis of each of the eight tubes 23, with the switch in normal position, at an acute vertical angle with respect to the normally horizontal axis ofthe particular tube 22 to which the re-' spective tube 23 is connected and at an acute projected horizontal angle with respect to a radial line running fromthe center of the base to the, point of junction be-. tween the particular tubes 22 and 23. These angles are Patented Apr. 17, 1962 Fromthe description thus far given, it can be seen that, I

by tilting the block 15 in a given direction, the liquid conductor 21 can be made to flow from chamber 20 through particular ones of the radial tubes 22 and into the tubes 23. Tubes 22 thus act to place the tubes 23 in flow communication with chamber 20 and tubes 22 also act to divide the pool of mercury so as to reduce splashing. In association with chamber 20 is a threaded metallic conducting stud or electrode 24 having a pair of lock nuts 25 resting on top face 16 and which extends through block .15 to come into firm electrical contact with a circular metallic conducting plate 26 cemented to a circular plug 27 which in turn is cemented into the bottom face 17 of block 15. Plate 26 serves the purpose of providing a relatively large conducting area with which liquid conductor 21 may make contact which in turn increases the strength of the electrical contact between the liquid conductor 21 and electrode 24 in both upright and tilt positions.

Electrode 24 acts as a common electrode and in the end of each of the tubes 23 are other electrodes 27 mounted in circular non-conductive plugs 28 cemented in the inside walls of tubes 23. Plugs 28 act to close the ends of tubes 23 so as to prevent the escape of the liquid conductor 21 and air and both the electrodes 27 and plugs 28 are threaded so as to allow each of the electrodes 28 to be individually positioned with respect to the tubes 23 in which each is mounted and with respect to chamber 20 in which liquid conductor 21 is normally confined. Once positioned, lock nuts 29 maintain such position and also act as means for holding wire conductors leading from the electrodes. Unlike some prior art devices having a bulb and fixed electrodes located in the ends of arms radiating outwardly, the converging sloping arrangement of my tubes insures a compact design and also insures that at all normal angles 'of tilt the liquid conductor will surround the electrode and make good electrical contact.

From the foregoing, -it will be appreciated that since tubes 23 are, in elfect, closed end tubes whenever block 15 is tilted, the liquid conductor 21 will tend to compress the air in' those closed tube ends into which it flow-s.

tilted in the direction indicated, the conducting liquid 21 completes a circuit between electrode 24 and electrode 27 but not between electrode 24 and electrode 27". With a battery 35 and lamps 36, 37 connected as indicated in FIGURE 6, lamp 36 would light whereas lamp 37 would not light. Upon block 15 being tilted back to its normal upright position, lamp 36 will, of course, go out as the conducting path between electrodes 27" and 24 is broken. From this description it can be seen that each electrode 27 can be individually positioned to a particular angle of til-t and thus the switch can be used to control one circuit at one angle of tilt and another circuit at another angle of tilt and this can be accomplished even in essentially the same direction of tilt by selecting two adjacent electrodes 27 and positioning them differently.

In FIGURE 7, an alternative circuit scheme is employed for utilizing the switch of FIGURES 1 through Therefore, the liquid conductor may be slow in'pr'ovidin'g a conducting path between electrode 24 and a particular electrode 27 and especially so when the particular electrode 2-7 is positioned so as to extend only slightly into its respective tube 23, such as would correspond to a relatively large angle of tilt. In my invention, I use this compression effect as a means of controlling the rate at which the. liquid conductor flows by providing near the closed end of each tube'23 an'air control 30. Air control 30 resides in a housing 30' which is cemented to the'side of the tube 23 and includes a needle valve 31 having a seat 32. A port 33allows air to enter from and exhaust to the outside and aport 34 allows air to enter 'and leave the tube as indicated by the arrows'in FIGURE 5'. By controlling the position of needle valve 31,- the rate at which air enters and leaves and thus the rate at which the liquid conductor flows into and 'from a particular tube 23 and thus the rate at which a particular conductpath 'is completed and broke'n'can thus be regulated.

Theswitchthus far described can obviouslybe used in many ways to operate relays, disconnect ignition circuits on tractors and the like. By way of example only, two such uses are illustrated in FIGURES 6 and 7. In FIG- URE 6, the svvitchis shown tilted in a particular direction and with all but two ofthe tubes 23 cut away to indicate how the switch operates. The electrode designated 27' is adjusted so as to extend further into itstube.

2 3 than does the electrode designated '27,". Thus, on being Here, the heavy dots 38 on FIGURE 7 represent the electrodes 27 and the central heavy dot 39 represents the electrode 24. As indicated, all of the electrodes 27 are connected together and to ground through a lamp 40, whereas electrode 24 is connected to ground through a battery 41. With a circuit arrangement of this kind and with all the electrodes 27 adjusted to the same position the electrical device to be energized, as represented by lamp 40, will have current passed through it whenever the switch is tilted in any direction beyond the angle to which the electrodes 27 have been adjusted. On the' other hand, if certain of the electrodes 27 are adjusted to one position and others of the electrodes :27 are adjusted to another position, lamp 40 will light at diflierent angles of tilt depending on the direction toward which the block 15 is tilted.

While not shown, another means of using the switch is native form of the invention is to use a plurality such as' two adjustable electrodes in each of the tubes 23 and this embodiment is indicated in FIGURES 8 and 9 which show only the closed end of the tube 23 and the arrangement of a pair of electrodes. In these FIGURES 42, 43 represent a pair of adjustable elect'rodeshaving lock nuts 44,;45 respeetively. The mounting arrangement for electrodes 42, 43 is generally the same as that employed for the s'ingle electrodes 27. Electrodes 42, 43 are threaded and pass through a non-conductive plug 46, indicated by dotted lines, through which electrodes 42, 43are'threaded plug 46 being cemented to the inside wall of tube 23 as in the case of plug 28. FIGURE 8 shows one "circuit arrangement in which electrodes '42, 43 are positioned so as to come in contact with the liquid at essentially the same angle of tilt and, in this case, electrode 42 is connected 'to ground through a battery 47 and electrode 45 is connected to ground through a lamp 48 No common ground is employed in this example which means that current will pass through the circuit device represented by lamp 48 whenever the corresponding tube 23 is tilted in the'proper direction and at a suflicient angle to cause the liquid conductor 21 to bridge the ends ot the elee me e Previously he speed at which this bridging actionftakes place may be controlled by air control 30.

in FIGURE 9, electrodes '42, 43; are set at diflerent positions and are groundedthrough lamps 49, 50. In

the. circuitfillustrated, the heavy dot J50 schematically? represents thepreviouslymentioned common electrode 24, represented'as being grounded'thro'ugh a battery In this example, it will be seen that if the switch is being used to control the ignition circuit of a machine such as a prime mover, lamp 49 could be used as a warning of a tilt situation and lamp 50 could signify a dangerous situation or lamp 50 could be replaced by a suitable relay to actually break the ignition circiut and stop the prime mover. While not shown in the drawings, it is also ap parent that double electrodes could be provided in certain of the tubes 23 and single electrodes in the remaining tubes 23 so as to provide different types of circuit control in diiierent directions of tilt.

While not necessary to carrying out the invention, a preferred material to be employed for block 15, tubes 22, tubes 23 and plugs 27, 28 and 46 is a transparent, nonconductive material since the necessary insulation between electrodes is established and the location of the liquid conductor and the various electrodes can be seen at all times. An alternative scheme is to employ transparent, non-conductive material for the tubes and a conducting material for block 15. By grounding this metal block and consequently liquid conductor 21, electrode 2A may be eliminated since block 15 may now serve as the common electrode.

Another form of the invention, not shown in the drawings, which I have found satisfactory but somewhat more difiicult to manufacture is to use a solid, cylindrical block of non-conductive, transparent material and bore the tubes and channels in this solid. The radial channels, corresponding to holes 19, are achieved by drilling in horizontally through the side of the block slightly above its base and to the center which also forms the necessary liquid conductor chamber. The ends of these radial holes are then plugged and additional holes representing the sloping and converging channels formed by the previously mentioned tubes 23 are drilled in from the top of the block to connect with the respective radial channels. The air controls are placed in suitable recesses formed adjacent the channels at the top of the block.

The invention may also be employed in a metal housing and one example of how this is accomplished is illustrated in FIGURE in which the representative tube 23 is here assumed to be of a metallic conducting material, which is grounded through a battery 53. The electrode 27 of FIGURE 10 is grounded through lamp 54 and is insulated from tube 23' by means of the nonconductive plug 55 through which electrode 27 is threaded and which acts to insulate electrode 27 from tube 23. In this example, as the tube 23' is tilted, a position will be reached as illustrated in FIGURE 10 at which the liquid conductor 21 will bridge the space between tube 23 and electrode 27 which will complete the circuit path and cause lamp 54 to light. These alternative forms, of course, retain the many basic characteristics of the invention.

Having explained my invention, I claim:

1. A position sensitive gravity operated liquid conductor electrical switch comprising a normally upright base including a centrally located liquid holding enclosed cylinder shaped chamber, hollow tubes located at spaced intervals on the periphery of and in flow communication with said chamber, each tube being fixed to said base and sloping upwardly and inwardly at an acute vertical angle with respect to the normal plane of said base and at an acute projected horizontal angle with respect to a horizontal radial line drawn from the center of said base through the bottom end of said tube, closing means in each of said tubes acting to close the upper ends thereof, electrode means mounted in each of said closing means, liquid conductor filling a portion of said chamber and electrically insulated from said electrode means, said switch being adaptable to tilt whereby to cause said liquid conductor to flow in the direction of'tilt and complete electrical circuits including said liquid conductor and those electrode means placed in contact therewith during said tilt.

2. A switch as claimed in claim 1 and including additional electrode means electrically insulated from said first mentioned electrode means and mounted in said chamber so as to be in continuous electrical contact with said liquid conductor whereby to serve as a common electrode with respect to each of said first mentioned electrode means 3. A switch as claimed in claim 1 wherein said elec- 4. A switch as claimed in claim 1 including air control I means associated with said tubes whereby to control the rate at which said liquid conductor flows and makes contact with said electrode means.

5. A switch as claimed in claim 3 and including air control means in said tubes whereby to control the rate at which said liquid conductor flows and makes contact with said electrode means.

6. A position sensitive gravity operated liquid conductor electrical switch comprising a normally upright base including a centrally located liquid holding enclosed cylinder shaped chamber, hollow tubes located at spaced intervals on the periphery of and in flow communication with said chamber, each tube being fixed to said base and sloping upwardly and inwardly at an acute vertical angle with respect to the normal plane of said base and at an acute projected horizontal angle with respect to a horizontal radial line drawn from the center of said base through the bottom end of said tube, closing means in each of said tubes acting to close the upper ends thereof,

electrode means mounted in each of said closing means, liquid conductor filling a portion of said chamber and I electrically insulated from said electrode means, additional electrode means electrically insulated from said first mentioned electrode means and mounted in said chamber so as to be in continuous electrical contact with said liquid conductor whereby to serve as a common electrode with respect to each of said first mentioned electrode means, said switch being adaptable to tilt whereby to cause said liquid conductor to flow in the direction of tilt and complete electrical circuits including said liquid conductor and those of said first mentioned electrode means placed in contact therewith during said tilt, said first mentioned electrode means being adjustable in position with respect to said chamber whereby to control the angle of tilt at which said liquid conductor comes in contact with said first mentioned electrode means and including air control means associated with said tubes whereby to control the rate at which said liquid conductor flows and makes contact with said first mentioned electrode means.

7. A switch as claimed in claim 1 wherein said base and tubes are composed of transparent, electrically nonconductive material.

8. A switch as claimed in claim 1 wherein said electrode means comprises a single contact rod electrically insulated from said liquid conductor and located in each of said closing means.

9. A switch as claimed in claim 1 wherein said electrode means comprise a plurality of contact rods electrically insulated from each other and from said liquid conductor means and mounted in each of said closing means.

I 10. A switch as claimed in claim 9 wherein each of said plurality of contact rods is adjustable in position with respect to said chamber thereby enabling the electrode means in each of said tubes to be adjusted to a plurality of successive angles of tilt thus enabling the completion of circuits at each of said angles.

11. A switch as claimed in claim 1 wherein said electrode means comprises a pair of contact rods electrically insulated from each other and from said liquid conductor means and mounted in each of said closing means.

12. A switch as claimed in claim 11 wherein each member of said pair of rods is adjustable in position with respect to said chamber thereby enabling the electrode means in each of said tubes to be adjusted to two successive angles of tilt thus enabling the completion of circuits at each of said angles.

13. A switch as claimed in claim 1 wherein said base is composed of an electrically conductive material and said tubes are composed of transparent electrically nonconductive material thereby enabling said base to act as a common electrode with respect to each of said electrode means and said tubes to act as a means of visually observing the location of said liquid conductor and said electrode means.

14. A switch as claimed in claim 1 wherein said base and tubes are each composed of an electrically conductive material and said liquid conductor is in continuous electrical contact therewith thereby enabling said conductive material to be included in completing said circuits.

15. A switch as claimed in claim 1 and including horizontally disposed channels within said base radiating from said chamber and located between said chamber and said tubes and as a part of said flow communication between said chamber and said tubes whereby to act as containers for said liquid conductor prior to its entry into said tubes.

16. A switch as claimed in claim 15 and wherein said electrode means are adjustable in position with respect to said chamber whereby to control the angle of tilt at which said liquid conductor comes in contact with said electrode means.

17. A switch as claimed in claim 16 and including air control means in said tubes whereby to control the rate at which said liquid conductor flows and makes contact.

18. A switch as claimed in claim 17 wherein said base and tubes are composed of transparent, electrically nonconductive material.

'19 A switch as claimed in claim 17 wherein said electrode means comprises a single contact rod electrically insulated from said liquid conductor and located in said closing means.

2 0. A switch as claimed in claim 15 wherein said electrode means comprise a plurality of contact rods electrically insulated from each other and from said liquid conductor and mounted in each of said closing means.

21. A switch as claimed in claim 20 wherein each of said plurality of rods is adjustable in position with respect to said chamber thereby enabling the electrode means in each of said tubes to be adjusted to a plurality of suc cessive angles of tilt thus enabling the completion of circuits at each of said angles.

22. A switch as claimed in claim 15 wherein said base and tubes are each composed of an electrically conductive material and said liquid conductor is in continuous electrical contact therewith thereby enabling said conductive material to be included in completing said circuits.

23. A switch as claimed in claim 15 wherein said base is composed of an electrically conductive material and said tubes are composed of transparent electrically nonconductive material thereby enabling said base to act as a common electrode with respect to eachof said electrode means and said. tubes to act as a means of visually trode means.

24. A switch as claimed in claim 17 and including additional electrode means electrically insulated from said first mentioned electrode means and mounted in said chamber so as to be in continuous electrical contact with said liquid conductor whereby to serve as a common electrode with respect to each of said first mentioned electrode means.

25. A switch as claimed in claim 6 wherein said electrode means comprise a plurality of contact rods electrically insulated from each other and from said liquid conductor means and mounted in each of said closing means and wherein each of said plurality of rods is adjustable in position with respect to said chamber thereby enabling the electrode means in each of said tubes to be adjusted to a plurality of successive angles of tilt thus enabling the completion of circuits at each of said angles.

1,867,278 Pensrum July 12, 1932 Henrici Aug. 15, 19.44 V 

